[Gluster-users] Zero byte versions in DHT volume

[Dan Bretherton]

Dear All,

I have found a large number of files like the one below in a DHT volume.

---------T  1 nobody nobody     0 2010-05-01 18:34 d80bao.daj0710

For those I have checked, a real file (i.e. non-zero size and normal
permissions and ownership) exists on one brick and its zero byte counterpart
is on one of the other bricks. I originally found these files by looking in
the individual server bricks, but I discovered that I can also find them
using the "find" command in the glusterfs DHT volume itself.  However,
listing a directory containing these files with "ls" does not list the zero
byte versions, but instead two copies of the normal versions are shown.
Does anybody have an idea what is going on?  This strange behaviour is
clearly going to confuse some users, and there are sometimes also long
delays when listing the affected directories.  I am using GlusterFS version
3.0.3 now but I also noticed this behaviour in 2.0.8.  My client and server
volume files are shown below.

Regards,
Dan Bretherton.

#
##
### One of the server vol files ###
##
#
volume posix1
  type storage/posix
  option directory /local
end-volume

volume posix2
  type storage/posix
  option directory /local2/glusterfs
end-volume

volume posix3
  type storage/posix
  option directory /local3/glusterfs
end-volume

volume locks1
    type features/locks
    subvolumes posix1
end-volume

volume locks2
    type features/locks
    subvolumes posix2
end-volume

volume locks3
    type features/locks
    subvolumes posix3
end-volume

volume io-cache1
  type performance/io-cache
  subvolumes locks1
end-volume

volume io-cache2
  type performance/io-cache
  subvolumes locks2
end-volume

volume io-cache3
  type performance/io-cache
  subvolumes locks3
end-volume

volume writebehind1
  type performance/write-behind
  subvolumes io-cache1
end-volume

volume writebehind2
  type performance/write-behind
  subvolumes io-cache2
end-volume

volume writebehind3
  type performance/write-behind
  subvolumes io-cache3
end-volume

volume brick1
    type performance/io-threads
    subvolumes writebehind1
end-volume

volume brick2
    type performance/io-threads
    subvolumes writebehind2
end-volume

volume brick3
    type performance/io-threads
    subvolumes writebehind3
end-volume

volume server
    type protocol/server
    option transport-type tcp
    option auth.addr.brick1.allow *
    option auth.addr.brick2.allow *
    option auth.addr.brick3.allow *
    option listen-port 6996
    subvolumes brick1 brick2 brick3
end-volume

#
##
### Client vol file ###
##
#
volume remus
    type protocol/client
    option transport-type tcp
    option remote-host remus
    option remote-port 6996
    option remote-subvolume brick3
end-volume

volume perseus
    type protocol/client
    option transport-type tcp
    option remote-host perseus
    option remote-port 6996
    option remote-subvolume brick1
end-volume

volume romulus
    type protocol/client
    option transport-type tcp
    option remote-host romulus
    option remote-port 6996
    option remote-subvolume brick1
end-volume

volume distribute
    type cluster/distribute
    option min-free-disk 20%
    #option lookup-unhashed yes
    subvolumes remus perseus romulus
end-volume

volume writebehind
  type performance/write-behind
  subvolumes distribute
end-volume

volume io-threads
  type performance/io-threads
  subvolumes writebehind
end-volume

volume io-cache
    type performance/io-cache
    option cache-size 512MB
    subvolumes io-threads
end-volume

volume main
  type performance/stat-prefetch
  subvolumes io-cache
end-volume


-- 
Mr. D.A. Bretherton
Reading e-Science Centre
Environmental Systems Science Centre
Harry Pitt Building
3 Earley Gate
University of Reading
Reading, RG6 6AL
UK

Tel. +44 118 378 7722
Fax: +44 118 378 6413